<!DOCTYPE html>
<html>
<head lang="en">
    <meta charset="UTF-8">
    <title>计算器</title>
    <link rel="stylesheet"  type="text/css"  href="calculator.css">
    <script src="calculator.js"></script>
</head>
<body>
    <div class="background_area" >
        <div class="calculator">
            <div id="calculator_text">计算器</div>
            <div id="display"  >0</div>
            <table class="key_table" id="key_table" >
               <tbody>
               <tr >
                   <td class="number_key"  id="clear"  onclick="clear_display()">c</td>
                   <td class="number_key"  id="delete_key" onclick="delete_key()">⬅</td>
                   <td class="number_key"  onclick="click_number('*')">*</td>
                   <td class="number_key" onclick="click_number('/')">/</td>
               </tr>
               <tr>
                   <td class="number_key" onClick="click_number(7)">7</td>
                   <td class="number_key" onClick="click_number(8)">8</td>
                   <td class="number_key" onClick="click_number(9)">9</td>
                   <td class="number_key"  onclick="click_number('%')">%</td>
               </tr>
               <tr>
                   <td class="number_key" onClick="click_number(4)">4</td>
                   <td class="number_key" onClick="click_number(5)">5</td>
                   <td class="number_key" onClick="click_number(6)">6</td>
                   <td class="number_key"  onclick="click_number('-')">-</td>
               </tr>
               <tr>
                   <td class="number_key" onClick="click_number(1)">1</td>
                   <td class="number_key" onClick="click_number(2)">2</td>
                   <td class="number_key" onClick="click_number(3)">3</td>
                   <td class="number_key" rowspan="2" id="equality" onClick="calculation_result()">=</td>
               </tr>
               <tr>
                   <td class="number_key" onClick="click_number(0)" >0</td>
                   <td class="number_key"  onclick="click_point()">.</td>
                   <td class="number_key"  onclick="click_number('+')">+</td>
               </tr>
               </tbody>
            </table>
        </div>
    </div>
</body>
</html>